Alert

The alert component is designed to notify you when problematic issues arise. For example, if the garage door is left open, the alert component can be used remind you of this by sending you repeating notifications at customizable intervals. This is also used for low battery sensors, water leak sensors, or any condition that may need your attention.

Alerts will add an entity to the front end only when they are firing. This entity allows you to silence an alert until it is resolved.

When using the alert component, it is important that the time zone used for Home Assistant and the underlying operating system match. Failing to do so may result in multiple alerts being sent at the same time (such as when Home Assistant is set to the America/Detroit time zone but the operating system uses UTC).

Basic Example

The alert component makes use of any of the notifications components. To setup the alert component, first, you must setup a notification component. Then, add the following to your configuration file:

done_message (Optional): A message sent after an alert transitions from on to off. Is only sent if an alert notification was sent for transitioning from off to on.

entity_id (Required): The ID of the entity to watch.

state (Optional): The problem condition for the entity. Defaults to on.

repeat (Required): Number of minutes before the notification should be repeated. Can be either a number or a list of numbers.

can_acknowledge (Optional): Allows the alert to be unacknowledgeable. Defaults to true.

skip_first (Optional): Controls whether the notification should be sent immediately or after the first delay. Defaults to false.

notifiers (Required): List of notification components to use for alerts.

In this example, the garage door status (input_boolean.garage_door) is watched and this alert will be triggered when its status is equal to on. This indicates that the door has been opened. Because the skip_first option was set to True, the first notification will not be delivered immediately. However, every 30 minutes, a notification will be delivered until either input_boolean.garage_door no longer has a state of on or until the alert is acknowledged using the Home Assistant frontend.

For notifiers that require other parameters (such as twilio_sms which requires you specify a target parameter when sending the notification), you can use the group notification to wrap them for an alert. Simply create a group notification type with a single notification member (such as twilio_sms) specifying the required parameters other than message provided by the alert component:

Complex Alert Criteria

By design, the alert component only handles very simple criteria for firing. That is, it only checks if a single entity’s state is equal to a value. At some point, it may be desirable to have an alert with a more complex criteria. Possibly, when a battery percentage falls below a threshold. Maybe you want to disable the alert on certain days. Maybe the alert firing should depend on more than one input. For all of these situations, it is best to use the alert in conjunction with a Template Binary Sensor. The following example does that.

This example will begin firing as soon as the entity sensor.motion’s battery attribute falls below 15. It will continue to fire until the battery attribute raises above 15 or the alert is acknowledged on the frontend.

Dynamic Notification Delay Times

It may be desirable to have the delays between alert notifications dynamically change as the alert continues to fire. This can be done by setting the repeat configuration key to a list of numbers rather than a single number. Altering the first example would look like the following.

Now the first message will be sent after a 15 minute delay, the second will be sent 30 minutes after that, and a 60 minute delay will fall between every following notification. For example, if the garage door opens at 2:00, a notification will be sent at 2:15, 2:45, 3:45, 4:45, etc., continuing every 60 minutes.